U.S. Pat. No. 4,609,574 (issued on Sept. 2, 1986, Dow Corning Corp.) discloses crosslinkable compositions which are used for the production of non-stick coatings and which comprise an alkenyl-functional organopolysiloxane in which a maximum of 10% of all the organic radicals are alkenyl groups and a methylhydridopolysiloxane having at least 3 Si-bonded hydrogen atoms per molecule, the ratio of Si-bonded hydrogen atoms to the alkenyl groups being 0.8 to 1.5. EP 523 660 A1 (published on Jan. 20, 1993, Wacker-Chemie GmbH) and the corresponding U.S. Pat. No. 5,241,034 describe compositions of alkenyl organosilicon compounds, hydridosiloxane cross-linking agents, catalyst and, optionally, initiator, the ratio of Si-bonded hydrogen to alkenyl groups preferably being 1 to 3. U.S. Pat. No. 5,145,932 (issued on Sept. 8, 1992, Toray Silicon Co., Ltd.) discloses formulations which comprise an alkenylorganopolysiloxane having at least two alkenyl groups per molecule, hydridoorganosiloxane crosslinking agents having at least two SiH groups. catalyst and inhibitor, and organopolysiloxanes which comprise neither Si-bonded hydrogen nor alkenyl groups. EP 444 960 A2 (published on Sept. 4, 1991, Shin-Etsu Chemical Co., Ltd.) describes addition-crosslinking organopolysiloxane compositions which comprise an organopolysiloxane containing vinyl groups and having Si-bonded hydrogen atoms, an organohydridosiloxane and a catalyst. In the J. of Applied Polymer Sci. 47, 2257 (1993) Stein et al., compositions of vinylsiloxane, hydridosiloxane, platinum catalyst and inhibitor are investigated for the nature of the network obtained after curing, it being pointed out that, although an excess of SiH is necessary to increase the rate of curing, on the other hand this has an interfering effect in the network and changes the physical properties of the coating by post-curing effect.